While astronomers are anxiously awaiting the deployment of the joint NASA–ESA–CSA James Webb Space Telescope – with its state-of-the-art infrared resolution and sensitivity – the Hubble telescope is not going down with a whimper. In a telescopic “Hold my beer and watch this” moment, NASA announced that astronomers using the Hubble Space Telescope tracked five of those mysterious fast radio bursts (FRBs) to the spiral arms of five distant galaxies, helped rule out some probable causes and may have proved where they actually come from. You go, Hubble!
“A galaxy's spiral arms trace the distribution of young, massive stars. However, the Hubble images reveal that the FRBs found near the spiral arms do not come from the very brightest regions, which blaze with the light from hefty stars. The images help support a picture that the FRBs likely do not originate from the youngest, most massive stars.”
In a NASA press release prior to the publication of the Hubble results in an upcoming edition of The Astrophysical Journal, Alexandra Mannings of the University of California, Santa Cruz, the study's lead author, reveals the first surprise from Hubble – the FRBs are coming from strong, young bulked-up stars that hang out and show off in the arms of the galactic spirals like bodybuilders on a beach. That rules out one probable cause of FRBs – explosive destruction of massive young stars which generate gamma-ray bursts. It also rules out mergers or collisions between neutron stars – these dead star explosions take billions of years and aren’t found in the spiral arms of older galaxies that are no longer creating new stars.
The latest hot new theory on the source of FRBs is magnetars -- last year, fast radio burst SGR 1935+2154 in the Milky Way was positively identified as a magnetar, and astronomers began looking for more of these highly magnetic dead stars. They should have asked Hubble first, says team member Wen-fai Fong of Northwestern University in Illinois.
“Owing to their strong magnetic fields, magnetars are quite unpredictable. In this case, the FRBs are thought to come from flares from a young magnetar. Massive stars go through stellar evolution and becomes neutron stars, some of which can be strongly magnetized, leading to flares and magnetic processes on their surfaces, which can emit radio light. Our study fits in with that picture and rules out either very young or very old progenitors for FRBs."
These new discoveries also show that astronomers need to be looking for FRBs in massive young galaxies with star-generating spiral arms. That eliminates dwarf galaxies which lack those arms. ‘Puny, pathetic galaxies’ as Arnold Schwarzenegger might say.
For the anthropomorphics among you, imagine the Hubble Telescope flexing its solar panels, strutting around the Earth and staring down at the still grounded Webb telescope, saying “Who da space telescope? WHO da space telescope?”
Yes, it’s that kind of moment.